U.S. Congressman Jesse Jackson Jr. is being treated for bipolar II depression, according to the Mayo Clinic.

The clinic updated the congressman's condition on its website, writing that after an extensive evaluation, "Congressman Jesse Jackson, Jr. is undergoing treatment for Bipolar II depression at Mayo Clinic in Rochester, Minn. Congressman Jackson is responding well to the treatment and regaining his strength."

The online announcement is the most detailed information given to the public since Jackson went on medical leave about two months ago. He was first hospitalized with mental illness on June 10.

According to the Mayo Clinic's website, bipolar disorder, previously called manic depression, is a treatable condition that affects parts of the brain that control emotion and can include extreme mood swings, which may be triggered by stressful events. The clinic offered a link for information on the disorder, http://www.mayoclinic.org/mcitems/mc5100-mc5199/mc5155-03.pdf

"They could have really elevated, super happy mood or they could be super irritable...have trouble sleeping, don't need sleep have super energy are very distractible. Their thoughts are racing, they speak very fast. They engage in impulsive, reckless behaviors potentially," said UIC Psychiatrist Dr. Luan Phan.

Medications and psychotherapy are often used together as treatment. Dr. Phan says bipolar depression is treatable, but that it requires ongoing medication and psychiatric care.

Last week, his wife, Chicago Alderman Sandi Jackson, said, "I have every confidence in the doctors at Mayo that they will come up with the right combination of medications that will get him back to us sooner than later."

The congressman will presumably continue medication after leaving the hospital.

Neither Jackson's family nor his doctors at the Mayo Clinic are offering a timeline for his recovery, the political clock is ticking.

"When you have a mental illness that can effect a person's ability to critically think, we're at a point I think he needs to demonstrate, there has to be a debate -- there needs to be a debate where he comes in front of the people and demonstrates he's on his game," said Republican Brian Woodworth, who is running against Jackson in the November election.

"I believe he has now disqualified himself," said Marcus Lewis, an independent candidate also running against Jackson.

Jackson's two opponents this fall speculate Democrats may be trying a switch-a-roo. August 23rd is the deadline to replace a candidate on the November ballot. If Jackson Jr. agrees to step-aside, one theory is committeeman might agree to replace him with his wife: Alderman Sandi Jackson. Despite her husband's illness, she continues to send out invitations to fundraisers.

"I wonder why you're doing that when your next race is two years away? So, they want to keep this thing like an heirloom in the family," said Lewis.

A spokesman for Jackson Jr. Monday night denies plans are in the works for him to step aside. Instead, the spokesman says, plans for jackson's re-election campaign are moving forward.

A visit this week by former congressman Patrick Kennedy may be meant to show people lead full and active lives after a depression diagnosis, but one thing to note is that Kennedy retired from the house less than four years after undergoing treatment.

Dr. Phan says many people treated for Bipolar II depression can live normal and productive lives.

"If they stick with treatment, and if the treatment works for them, they're just as functional as you and I," said Dr. Phan.

Dr. Phan said in normal circumstances bipolar disorder is diagnosed and treatment is determined within a couple of weeks. But he says there are cases where it can take longer to diagnose.

"Bipolar disorder is a very treatable disorder and when a patient is adherent, compliant with treatment they can achieve full functional status," Dr. Phan said.

According to the Mayo Clinic statement, Bipolar II is most likely caused by a "complex set of genetic and environmental factors." The statement mentioned Congressman Jackson underwent gastric bypass surgery for weight loss in 2004, but did not link that operation to Jackson's bipolar disorder.

Jackson is under investigation by the House Ethics Committee for his alleged role in a plot to buy Barack Obama's U.S. Senate seat as well as using a fundraiser to fly a mistress between Washington and Chicago.

Jackson was first hospitalized on June 10th for what his office called "exhaustion" and weeks later described as a "mood disorder".